418 NOTES FROM THE BOTANIC GARDENS, SYDNEY, 



it well watered, and exposed it to sunlight. The plants spread, 

 and continued to flower well into the month of May. Mr. 

 Brooks' plants naturally took longer to accustom themselves to 

 the greater change of conditions, but, early in April, they were 

 in full flower. Thus, the suggested experiment had succeeded. 

 It was plain that the condition necessary to produce flowers was 

 exposure of the growing plant to air and sunlight. 



I then tried the converse experiment of placing some of the 

 flowering plants in soil, at the bottom of a glass jar, which I 

 filled with water. They did not resent the sudden change, but 

 speedily grew out into the elongated form with longer leaves, 

 and now (in May) are producing the capsules of the submerged 

 form freely. 



The capsules of the submerged form closely resemble those of 

 the flowers, and, as no stamens are present, we have a clear case 

 of parthenogenesis. 



Glossostigma spathulatum Arnott [Scrophulariace^]. 



In another glass tank in the Gardens, were growing vigorously, 

 a number of plants of a Glossostigma, which, while spreading 

 freely in the water, never rose to the surface. The roots were 

 fixed in the soil at the bottom. These plants also bore capsules 

 of various stages, in none of which could I detect floral envelopes 

 or stamens. The plants had been growing for years in the tank, 

 but had never produced flowers. 



We experimented with these in the same way as with Elatine. 

 Mr. Brooks placed his in a flower-pot in ordinary mould, and 

 placed the pot in a large saucer filled with water. In about a 

 month, the plants had quite accommodated themselves to the 

 new habitat, and produced a number of tiny, blue, perfect 

 flowers. I arranged my plant in a diminutive, artificial pond I 

 had made, so that part of the creeping stem was fixed by the 

 roots to soil at the bottom, and the other part, unsevered, ex- 

 tended over a small bank of earth at the side of the pond. Thus, 

 part of the plant was submerged, and part exposed to air and 

 direct sunlight. It seemed at home at once, and both plants 

 grew quickly. The submerged part spread far and wide over 



